Two second-half goals in three minutes from Ryan Giggs and Wayne Rooney gave United a 2-0 victory over Schalke 04 to take into next week's second leg at Old Trafford.
Wayne Rooney (centre) hits a first-time shot past Manuel Neur to score Manchester United's second goal
'It was a tremendous performance,' said Ferguson, who is now set to clinch a place in the final for the fourth time on May 28 against either Barcelona or Real Madrid.
'We've found a way to play like this away from home in Europe in recent years. We've had some fantastic performances.
Juventus in 1999 will always be high on the list, but I think it's one of the best.'
Safe hands: Schalke's goalkeeper Manuel Neuer was the only positive on a disappointing night for the Germans
Schalke goalkeeper Manuel Neuer produced a string of outstanding saves, particularly from Javier Hernandez and Giggs in the first half, to save his side from a rout and Ferguson claimed it was his Mexico striker's disallowed effort just after the break that convinced United they could find a way through.
He added: 'In my time at United it's the finest display of goalkeeping against us. I think there was a frustration towards the end of first half when he saved from Ryan. The move broke down and the players started walking back I could sense their frustration.
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'The thing that broke the camel's back was Hernandez's goal that was ruled out for offside. It showed thatwe could beat the guy.'
Despite being linked with United, Neuer is destined to joined Bayern Munich in a ?20m deal when he leaves Schalke at the end of the season. 'I think we know that,' admitted Ferguson, who can now look forward to finally beating a German team overtwo legs at the fifth attempt. 'That's very welcome,' he said. 'I've waited a long time for it.'
Job done: Manchester United celebrate Wayne Rooney's goal that clinched the victory
Giggs became the oldest scorer in Champions League history at 37 years and 148 days when he broke Neuer's resistance after 67 minutes, with Rooney adding United's second two minutes later.
Giggs said: 'We knew that if we kept creating chances one would go in and hopefully I would get one on my left foot. Before the game we would have taken 2-0, but now we're slightly disappointed.'
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Rooney refused to write off a Schalkeside who stunned holders Inter Milan 5-2 in the San Siro in the first leg of their quarter-final.
He said: 'We're delighted with the performance. But Schalke are a good team and we can't take them lightly.We need to make sure we are professional.'
Neuer admitted that his team never got going in the game, saying: 'I think we showed too much respect from the start. We had trouble winning the ball and did not defend well.'
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